Abstract: The present invention relates to an openable roof having two pairs of half dome openable roofs provided on a ring shaped set roof having a flat upper surface. In the center of the set roof, an aperture is provided; this aperture being opened or closed by these two pairs of openable roofs. Furthermore, either respective pair of these two pairs of openable roofs may be selected and utilized to open and close the aperture as necessary.

Abstract: A dome shaped roof structure suitable for a stadium for indoor athletic sports is disclosed. The dome shaped roof structure comprises a main frame for covering the inside of the stadium and a reinforcing frame. The reinforcing frame comprises: cables disposed in the inner side of the main frame and extended radially from the central portion of the main frame to the bottom peripheral border; circular cables disposed concentrically about the peripheral border of the main frame; and strut members that have each upper end connected to the steel member of the main frame at an intersecting point of the radiating cables and the circular cables, and the strut members vertically supported by the radiating cables and the circular cables; and wherein tension is introduced to the radiating cables in the direction of the bottom peripheral border and the outer ends of the radiating cables are fixed with the main frame, so that the steel members of the main frame are thrust up by the strut members of the reinforcing frame.

Abstract: The present invention relates to an openable roof having two pairs of half dome openable roofs provided on a ring shaped set roof having a flat upper surface. In the center of the set roof, an aperture is provided; this aperture being opened or closed by these two pairs of openable roofs. Furthermore, either respective pair of these two pairs of openable roofs may be selected and utilized to open and close the aperture as necessary.

Abstract: A bar magnet and an instrument and method of manufacture thereof, in which the magnet is integrally formed of a single material and has circular magnetic poles at selected side portions thereof. The bar magnet is formed by snuggly fitting around an integral bar of magnetizable material, magnetic members of higher magnetic permeability than that of the magnetizable material of the integral bar, at a plurality of local locations along the length of the bar and applying a current to a coil surrounding the bar such that the bar is permanently alternately magnetized north and south axially along the sides of the bar. The coil extends axially up and surrounds the bar and metallic members, and is enclosed in a yoke. The bar magnet is applicable for use in extracting metallic substances from the stomachs of cattle.

Abstract: A rapid exhaust valve for use in a blood circulation stimulator which supplies and exhausts an air to and from an air bag provided on the human body, thereby subjecting to repeated pressure application and release.A valve box, which is provided with an exhaust port on the circumferential wall thereof, is provided with a flexible band valve diaphragm therein. If a compressed air is supplied into said valve box through a compressed-air supply pipe, said valve diaphragm is pushed by the pressure to close said exhaust port and a part of said valve diaphragm is projected into an air bag from an opening communicating with said air bag to allow the compressed air flow into said air bag. When the pressure in said air bag reaches high, said flexible valve diaphragm is deformed so that it may close said compressed-air supply pipe to release said exhaust port whereby rapidly discharging the compressed air out of said air bag.

Abstract: A tension structure having a curved surface comprises a group of metal strips to form the curved surface and each of the strips is pre-stressed under tension for stabilizing the structure. The tension is produced in the strips by a group of tension members generally having a curvature opposite to that of the strips, the strips and tension members being arranged to effect tension indirectly on each other through an intermediate means such as a group of intermediate members disposed therebetween or air serving as the intermediate means or directly. In some instances, the ground surface regarded as having an indefinite radius is utilized as equivalent to the tension members. The erection of the structure is available by the application of tension and the conventional scaffold usually required may be omitted.

Abstract: A blood circulation stimulator which helps to improve the circulation of blood by intermittently pressing the human body. It includes an air bag inflatable with compressed air, a solenoid valve for controlling an exhaust port in the compressed air supply line, and an electrical circuit for controlling the solenoid valve.